Let's try reviewing the taxes on a private window. It is the best place to identify if the duplication were caused by browser-related issues.
You can use these keyboard keys to open one:
Google Chrome: Ctrl + Shift + N
Mozilla Firefox: Ctrl + Shift + P
Microsoft Edge: Ctrl + Shift + P
Safari: Command + Shift + N
If it works, you can go back to a regular browser and clear its cache. A piled cache can also be the reason for some unexpected concerns on the opened pages.
We can also switch to a different supported browser like Google Chrome, Mozilla Firefox, Safari, or Microsoft Edge as alternative.